Definition of "Simple" :

noun: a person lacking intelligence or common sense

noun: any herbaceous plant having medicinal properties

adjective: easy and not involved or complicated

"A simple game."

adjective: apart from anything else; without additions or modifications

"The simple passage of time was enough."

adjective: unornamented

"A simple country schoolhouse."

adjective: lacking mental capacity and subtlety

adjective: (botany) of leaf shapes; of leaves having no divisions or subdivisions

adjective: having few parts; not complex or complicated or involved

"A simple problem."

adjective: exhibiting childlike simplicity and credulity